Two-dimensional transition metal dichalcogenide-based counter electrodes for dye-sensitized solar cells

Singh, Eric J.; Kim, Ki Seok; Yeom, Geun Young; Nalwa, Hari Singh

doi:10.1039/c7ra03599c

Cited by 185 publications

(92 citation statements)

References 389 publications

(427 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TMDs have many rich physical properties such as extremely weak phonon‐assisted photoluminescence (PL) in bulk structures, relatively strong PL yield in monolayer structures, strong valley‐dependent absorption in visible range, and strong nonlinear optical response . By taking advantage of these properties, significant progresses have been made in the development of electronic and optoelectronic technologies by these materials, such as photodetectors, field‐effect transistors, solar cells, light‐emitting diodes, valleytronics, integrated circuits, and so on.…”

Section: Introductionsupporting

confidence: 90%

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy

Zhu

Zhao

et al. 2018

Advanced Optical Materials

View full text Add to dashboard Cite

are new types of semiconductors in which adjacent layers are held by van der Waals force. [1] TMDs have many rich physical properties such as extremely weak phonon-assisted photoluminescence (PL) in bulk structures, relatively strong PL yield in monolayer structures, [2][3][4][5] strong valley-dependent absorption in visible range, [6][7][8] and strong nonlinear optical response. [9][10][11][12] By taking advantage of these properties, significant progresses have been made in the development of electronic and optoelectronic technologies by these materials, [13,14] such as photodetectors, [15] field-effect transistors, [16][17][18] solar cells, [19,20] light-emitting diodes, [21,22] valleytronics, [8,23] integrated circuits, [24] and so on.The exciton binding energy in the monolayer TMDs has been observed in the range of 0.1-1.1 eV, [25][26][27][28] which is larger than that in traditional bulk semiconductors and traditional quantum well. [29,30] This rich excitonic state makes it possible to observe the complex exciton dynamics at room temperature, [31] such as charged and neutral phase of carriers, [32] trions, [33] and biexciton. [34] Meanwhile, bounded exciton could not only dominate the optical response but also play an important role in the optoelectronic processes, such as photocurrent generation and photoconduction in TMD semiconductors. [33,35,36] As a typical TMD material, the bulk WSe 2 has an indirect bandgap of 1.2 eV, and it would transform to the ≈1.65 eV direct bandgap as decreasing to monolayer. [37,38] WSe 2 has been widely used in optoelectronic devices due to its high absorption coefficients in the visible range. Field-effect transistors based on single crystal WSe 2 have been achieved and a carrier mobility comparable to silicon at room temperature was demonstrated. [39] Besides, WSe 2 can also play an important role in the development of van der Waals heterostructures, [40][41][42] in which long-lived interlayer excitons have been observed.Recently, ultrafast time-resolved photoexcited carrier dynamics has been studied in layered TMDs by the most widely used tools, such as optical-pump optical-probe spectroscopy, [43] PL spectroscopy, [38] photocurrent spectroscopy, [36] and electroluminescence. [35,44] The prevalentThe dynamics of photoexcited species is quite important for the development of next-generation ultrafast optoelectronic devices based on transition metal dichalcogenides (TMDs). Herein, time-resolved optical pump terahertz (THz) probe spectroscopy, which is sensitive to both bounded excitons and free electrons/holes, is employed to study the dynamics of photo-induced carriers in the typical layered TMDs crystal tungsten diselenide (WSe 2 ). Initial photoexcitation could generate both free carriers and excitons. The free carriers decay followed by phonon-assistance (≈30 ps) and defect-assistance (≈200-280 ps). The excitons decay followed by the phonon-assisted recombination (≈100 ps) and the defect-induced exciton separation (≈40-200 ps). With the increasing of pump fluence, more f...

show abstract

Section: Introductionsupporting

confidence: 90%

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy

Zhu

Zhao

et al. 2018

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…LEDs, luminescent solar concentrators and related photonic technologies represent other platforms where Cs‐based perovskites can behave as core materials in combination with other recently emerged advanced concepts . In this scenario, Mn 2+ doping is currently considered one of the leading strategies to modify the optical and magnetic functionalities of nanocrystals of various chalcogenide and oxide semiconductors .…”

Section: Caesium‐doped Perovskites In Emerging Technologiesmentioning

confidence: 99%

“…LEDs, luminescent solarc oncentrators and related photonic technologiesr epresent other platforms where Cs-based perovskites can behavea sc ore materials in combination with other recently emerged advanced concepts. [244][245][246][247][248][249][250][251][252][253] In this scenario, Mn 2 + doping is currently considered one of the leadings trategies to modify the opticala nd magnetic functionalitieso f nanocrystals of variousc halcogenide ando xide semiconductors. [254] An interesting synergy between these materials chemistry features was proposed by Yuan et al,w ho synthesized as eries of Mn 2 + -doped CsPbCl 3 nanocrystals using reaction temperature and precursor concentration to tune Mn 2 + content up to 14 %.…”

Section: Caesium-doping In Other Perovskite Solar Cell Componentsmentioning

confidence: 99%

Caesium for Perovskite Solar Cells: An Overview

Bella

Renzi

Cavallo

et al. 2018

Chemistry A European J

150

View full text Add to dashboard Cite

Perovskite solar cells have the potential to revolutionize the world of photovoltaics, and their efficiency close to 23 % on a lab-scale recently certified this novel technology as the one with the most rapidly raising performance per year in the whole story of solar cells. With the aim of improving stability, reproducibility and spectral properties of the devices, in the last three years the scientific community strongly focused on Cs-doping for hybrid (typically, organolead) perovskites. In parallel, to further contrast hygroscopicity and reach thermal stability, research has also been carried out to achieve the development of all-inorganic perovskites based on caesium, the performances of which are rapidly increasing. The potential of caesium is further strengthened when it is used as a modifying agent of charge-carrier layers in solar cells, but also for the preparation of perovskites with peculiar optoelectronic properties for unconventional applications (e.g., in LEDs, photodetectors, sensors, etc.). This Review offers a 360-degree overview on how caesium can strongly tune the properties and performance of perovskites and relative perovskite-based devices.

show abstract

“…Dye sensitized solar cells (DSSCs) have attracted increasing attention because of their non-toxic and low cost. [1][2][3][4][5][6] Since the breakthrough energy conversion efficiency (h) achieved by Gratzel's group in 1991, related research on this topic has become very popular. 7 In the past two decades, attention has been focused on fabricating more efficient dyes and nding better photoanode materials to further improve the resulting photovoltaic performance.…”

Section: Introductionmentioning

confidence: 99%

Graphene based photoanode for DSSCs with high performances

Peng

Wang

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

show abstract

Two-dimensional transition metal dichalcogenide-based counter electrodes for dye-sensitized solar cells

Cited by 185 publications

References 389 publications

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy

Caesium for Perovskite Solar Cells: An Overview

Graphene based photoanode for DSSCs with high performances

Contact Info

Product

Resources

About

Two-dimensional transition metal dichalcogenide-based counter electrodes for dye-sensitized solar cells

Cited by 185 publications

References 389 publications

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe2 Crystal with Time‐Resolved Terahertz Spectroscopy

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe2 Crystal with Time‐Resolved Terahertz Spectroscopy

Caesium for Perovskite Solar Cells: An Overview

Graphene based photoanode for DSSCs with high performances

Contact Info

Product

Resources

About

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy

Competition between Free Carriers and Excitons Mediated by Defects Observed in Layered WSe₂ Crystal with Time‐Resolved Terahertz Spectroscopy